\\[-1.8ex] Soil Heterogeneity & $-$0.033$^{*}$ & $-$0.026 & $-$0.027 & $-$0.027 & $-$0.028 & $-$0.028 & $-$0.028 \\ 
  & (0.020) & (0.018) & (0.018) & (0.019) & (0.019) & (0.019) & (0.019) \\ 
\\[-1.8ex] 
Observations & 14,269 & 14,269 & 14,269 & 14,269 & 14,269 & 14,269 & 14,269 \\ 
R$^{2}$ & 0.620 & 0.625 & 0.626 & 0.626 & 0.627 & 0.627 & 0.627 \\ 
